Children with high functioning autism (HFA) are at heightened risk for anxiety disorders when compared with neurotypical children. The high prevalence rate of anxiety disorders in HFA is suggestive of a distinct subgroup of children on the autism spectrum-an "anxious-inhibited" subgroup. Due to complications that comorbid diagnoses can add to the adaptive functioning of children with HFA, and because the psychosocial intervention literature has been marked with few successes, researchers have recommended addressing specific symptoms and prevalent subgroups found among children with HFA. The proposed study is designed to examine the efficacy of a recently modified cognitive behavioral therapy (CBT) program in the remediation of anxiety symptoms in children with HFA. This study will include a pilot phase with 3 children with HFA ranging in age from 7-13 years, allowing further refinement and modification of the CBT manual. Thereafter, 28 children will be randomly assigned to either immediate treatment or waitlist control conditions; children and primary parents will be provided a multimodal CBT intervention in a clinic setting. Children assigned to the waitlist control group will receive the full treatment after 3 months. This experimental design will allow me to test the impact of CBT on children's anxiety and adaptive functioning. Measures of anxiety, social, academic, and daily living skills functioning, as well as treatment acceptability will serve as primary outcomes and will be assessed immediately following intervention and at 3 months post treatment.